[arch-general] problem compiling for i586 with new makepkg

[Travis Willard]

Just a hint, since you were looking to add i586 - find and sed are
your friends. :D

find -name PKGBUILD -exec sed -i '/^arch=/ { /i586/ !{
s/^arch=(/arch=(i586 / } }' {} \;

That will find every PKGBUILD and add i586 to the packages that don't
already have it.  Yay!